FILE - Then U.S. President Richard Nixon and then Chinese Premier Zhou Enlai review Chinese troops at Nixon's departure from Beijing to Hangchow to continue his China visit, Feb. 26, 1972. First lady Pat Nixon and National Securty adviser Henry Kissinger are seen walking behind Nixon and Zhou. At the height of the Cold War, U.S. President Richard Nixon flew into communist China's center of power for a visit that over time would transform U.S.-China relations and China's position in the world in ways that were unimaginable at the time. (AP Photo, File)